JP2011105484A - Device for detecting failure of electromagnetic brake - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a device for detecting a failure of an electromagnetic brake capable of detecting a failure of a current sensor and a mechanism failure of an electromagnetic actuator, which is applicable to a braking device with the electromagnetic actuator required to be miniaturized and quiet. <P>SOLUTION: The device includes an integrator 25 integrating an estimated speed of an armature 9 estimated by an armature speed calculator 21, a differentiator 24 differentiating the estimated speed of the armature estimated by the armature speed calculator 21 twice, and a brake contact 13 detecting the fact that the armature 9 is sucked by a brake coil 11. The device detects an abnormality of the brake device by comparing at least one of a difference between a preset displacement on completion of sucking operation in a normal condition and an output result of the integrator 25 on completion of the sucking operation, a difference between a preset displacement upon output of the brake contact 13 in a normal condition and an output result of the integrator 25 upon the output of the brake contact 13, and a difference between a preset applied acceleration during braking operation in a normal condition and an output result of the differentiator 24. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a failure detection device for an electromagnetic brake that detects an abnormality of a braking device that performs an opening operation by an electromagnetic actuator.

  As a conventional technique, the brake is released by energizing the electromagnetic coil and attracting the movable iron core facing the electromagnetic coil, and when the energization to the electromagnetic coil is interrupted, the movable iron core is separated by the repulsive force of the braking spring. In the electromagnetic brake that operates, the calculated voltage command value is calculated from the current value and coil resistance value of the electromagnetic coil detected by the sensor, and the calculated voltage command value is compared with the actual voltage command value. Thus, a technique for detecting an abnormality in an electromagnetic coil and a current sensor is known (see, for example, Patent Document 1).

  In another conventional technique, a change in the electromagnetic coil current value over time is continuously detected by a sensor as a means for detecting an abnormality in the braking device, and compared with a current waveform pattern in a normal state. A technique is known in which foreign matter biting between an electromagnetic coil and a movable iron core and an abnormality in a link mechanism are detected separately (for example, Patent Document 2).

JP 2008-150200 A (summary column, FIG. 1) Japanese Patent No. 2795152 (paragraph 0018, FIG. 5)

  However, with the technique disclosed in Patent Document 1, there is a problem that it is not possible to detect a mechanical failure such as a gap abnormality of the movable iron core only by detecting a resistance abnormality of the electromagnetic coil and an abnormality of the current sensor. is there. As a means for solving this problem, Patent Document 2 has been proposed. However, in the technique disclosed in Patent Document 2, an abnormality is detected by a current change caused by an inductance change of an electromagnetic coil. It is necessary to configure an electromagnetic actuator that changes the inductance of the electromagnetic coil during operation to some extent. For example, (1) increase the gap between the electromagnetic coil and the movable iron core, (2) increase the moving speed of the movable iron core, and (3) increase the electromagnetic attraction capability so that the movable iron core is not magnetically saturated. For example, to give a margin.

  However, in order to increase the gap between the electromagnetic coil and the movable iron core, or to allow a sufficient amount of electromagnetic attraction so that the movable iron core is not magnetically saturated, it is necessary to increase the adsorption surface between the electromagnetic coil and the movable iron core. Therefore, there is a problem that the brake device becomes larger. Further, if the moving speed of the movable iron core is increased, the collision noise of the braking surface due to the movement of the movable iron core, that is, the braking operation sound is increased, so that it is difficult to apply to a brake device installed in a place where quietness is required. There was a problem.

  The present invention has been made in view of the above problems, and can be applied to a braking device having an electromagnetic actuator that is required to be downsized and quiet, and can detect a failure of a current sensor and a mechanical failure of the electromagnetic actuator. An object of the present invention is to provide a brake failure detection device.

  An electromagnetic brake failure detection device according to the present invention is an electromagnetic brake failure detection device comprising a control device that excites a brake coil and causes the brake coil to attract an armature to release a braking force of the brake device. A voltage command calculation means for generating a voltage command for exciting the brake coil, a current detection means for detecting an excitation current of the brake coil, a voltage command value output from the voltage command calculation means, Coil resistance calculation means for estimating the resistance value of the brake coil from the current value of the brake coil detected by the current detection means, voltage command value generated by the voltage command calculation means, and brake estimated by the coil resistance calculation means Based on the resistance value of the coil and the current value of the brake coil detected by the current detection means, Armature speed calculating means for estimating the armature speed, integrating means for integrating the armature estimated speed estimated by the armature speed calculating means and outputting the result, and estimation of the armature estimated by the armature speed calculating means Differentiating means for differentiating the speed twice and outputting the result, a brake contact for detecting that the armature is attracted to the brake coil and outputting the result, and a suction operation in a preset normal state The difference between the displacement at the time of completion and the output result of the integration means at the completion of the suction operation, the displacement at the time of output of the brake contact in a preset normal state and the output result of the integration means at the time of output of the brake contact And the jerk during brake operation in a preset normal state and the differential means By comparing at least one of a difference between the force results, and the brake failure detection means for detecting an abnormality of the braking system, in which with a.

  According to the present invention, there is obtained an electromagnetic brake failure detection device that can be applied to a braking device having an electromagnetic actuator that is required to be small and quiet, and that can detect a failure of a current sensor and a mechanical failure of the electromagnetic actuator. be able to.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the whole elevator system containing the failure detection apparatus of the electromagnetic brake by Embodiment 1 of this invention. It is a block block diagram of the control apparatus used for the failure detection apparatus of the electromagnetic brake by Embodiment 1 of this invention. It is a flowchart which shows the operation | movement at the time of the brake attraction | suction of the control apparatus used for the failure detection apparatus of the electromagnetic brake by Embodiment 1 of this invention. It is a flowchart which shows the operation | movement at the time of the brake attraction | suction of the control apparatus used for the failure detection apparatus of the electromagnetic brake by Embodiment 1 of this invention. It is a graph which shows the time-dependent change of the applied voltage at the time of brake attraction | suction at normal time, a coil current, an estimated speed, and an estimated displacement of the failure detection apparatus of the electromagnetic brake by Embodiment 1 of this invention. It is a figure explaining operation | movement of the failure detection apparatus of the electromagnetic brake by Embodiment 1 of this invention. It is a figure explaining operation | movement of the failure detection apparatus of the electromagnetic brake by Embodiment 1 of this invention. It is a figure explaining operation | movement of the failure detection apparatus of the electromagnetic brake by Embodiment 1 of this invention. It is a block block diagram of the control apparatus used for the failure detection apparatus of the electromagnetic brake by Embodiment 2 of this invention. It is a flowchart which shows the operation | movement at the time of the brake attraction | suction of the control apparatus used for the failure detection apparatus of the electromagnetic brake by Embodiment 2 of this invention. It is a flowchart which shows the operation | movement at the time of the brake attraction | suction of the control apparatus used for the failure detection apparatus of the electromagnetic brake by Embodiment 2 of this invention. It is a block block diagram of the control apparatus used for the failure detection apparatus of the electromagnetic brake by Embodiment 3 of this invention.

  Preferred embodiments of a failure detection device for an electromagnetic brake according to the present invention will be described below with reference to the accompanying drawings. It should be noted that the present invention is not limited to this embodiment, and includes various design changes.

Embodiment 1 FIG.
1 is a diagram showing an entire elevator system including a failure detection device for an electromagnetic brake according to Embodiment 1 of the present invention. In FIG. 1, an elevator car 1 and a counterweight 2 are suspended in a hoistway and are raised and lowered in the hoistway by the driving force of a hoisting machine. The hoisting machine includes a sheave 4 of the hoisting machine around which the main rope 3 is wound, a hoisting motor 5 that rotates the sheave 4, and a brake rotating body installed on a shaft that couples the hoisting motor 5 and the sheave 4. The brake drum 6 and the electromagnetic brake device 7 for braking the rotation of the sheave 4 are provided.

  The electromagnetic brake device 7 includes a brake shoe 8 that is brought into contact with and separated from the brake drum 6, an armature 9 that is connected to the brake shoe 8, a brake spring 10 that presses the brake shoe 8 against the brake drum 6, and a brake coil 11. And a brake contact 13 for detecting that the armature 9 is attracted to the electromagnet 12. The electromagnet 12 attracts the armature 9 against the brake spring 10 by generating an electromagnetic force, and separates the brake shoe 8 from the brake drum 6.

  The voltage of the brake coil 11 is controlled by the control device 14, and a detection signal from the current detector 15 which is a current detection means for detecting a current value supplied to the brake coil 11 and a detection signal from the brake contact 13 are input. ing.

  The control device 14 is provided in an elevator control device that controls the operation of the car 1. The elevator control device has a control panel (not shown) having an arithmetic processing unit (CPU), a storage unit (ROM, RAM, hard disk, etc.), and a signal input / output unit. The function of the control device 14 is realized by this control panel. Therefore, a program for realizing the above functions is stored in the storage unit of the control panel.

  Next, the operation at the time of brake suction will be described with reference to FIGS. 3, 4 and 5 together with the block diagram of the control device 14 shown in FIG. FIGS. 3 and 4 are flowcharts showing the operation of the control device 14 during brake suction, and FIG. 5 shows changes with time in applied voltage E, coil current i, estimated speed v, and estimated displacement x during normal brake suction. It is a graph.

  When the preparation to start raising / lowering the car 1 is completed, an initial value and a reference value for determining abnormality are input to the control device 9 as a brake suction command from the control panel. The brake suction command includes an initial value for performing calculation inside the control device 14 and a reference value for determining abnormality (STEP 1 in FIG. 3).

Based on the initial voltage E ₀ , the control gain K _p , the target speed value v _p , and the speed v calculated by the armature speed calculator 21, which is an armature speed calculation means, in the voltage command calculator 20 that is a voltage command calculation means. For example, as shown in the equation (1), the output of the voltage command value E corresponding to the armature speed v is started (STEP 2 in FIG. 3). However, the limiter 22 limits the upper limit of the voltage command value E to E _max (STEP 3 in FIG. 3).
E = E ₀ −K _P [v _P −v] (1)

  When the voltage E is applied to the brake coil 11, the actual current I of the brake coil 11 increases with a certain time constant as indicated by T1 to T2 in FIG. When the actual current I increases and the electromagnetic force generated in the electromagnet 12 including the brake coil 11 overcomes the force pressing the brake shoe 8 of the braking spring 10 against the brake drum 6, the armature 9 connected to the brake shoe 8 is moved to the electromagnet 12. The brake shoe 8 starts to be separated from the brake drum 6. At this time, an induced electromotive force is generated in a direction that prevents a change in magnetic flux due to the movement of the armature 9, and the actual current I decreases as indicated by T2 to T3 in FIG. In FIG. 5, the coil current i is shown as a change with time, but the tendency of the actual current I is the same as the change with time.

The current detector 15 detects the series of actual currents I and outputs a coil current value i. The armature speed calculator 21 receives a brake suction command, a voltage command E output from the voltage command calculator 20 via the limiter 22, and a coil current value i that is a detection signal from the current detector 15. Based on the voltage command value E, the coil current value i, and the previously set electromagnet inductance L, coil resistance value R, and coefficient: K _e in accordance with the brake operation command, for example, as shown in equation (2) The armature estimated speed v is calculated and output (STEP 4 in FIG. 3).
v = K _e [E-Ri-L (di / dt)] (2)
Therefore, by repeating the above STEP2 to STEP4, the armature speed at the time of brake suction can be reduced, and the collision sound of the braking surface, that is, the brake operation sound is reduced.

Brake contact 13 from the suction position to the electromagnet 12 and the armature 9 is completely adsorbed in the _normal, when the suction from the position distant _{x sw0 (i.e., x 0 -x sw0 <x)} , that the adsorption has been completed The ON signal shown is output. At this time, the output start position _xsw0 of the contact signal is adjusted in advance to be in a certain range at the factory.

  The brake abnormality detector 23 which is a brake abnormality detecting means includes an estimated jerk j calculated by a differentiator 24 which is a differentiating means based on an armature estimated speed v which is an output from the armature speed detector 21, and an integral. The estimated displacement x calculated by the integrator 25 as means, the detection signal from the brake contact 13, and the brake suction command are input (STEP 5 in FIG. 3). Further, the brake abnormality detector 23 has a timer (not shown) that sets T = 0 at the time of suction start, and counts the time from the start of suction.

The brake abnormality detector 23 detects an electromagnetic brake abnormality based on these input signals and a preset reference value. Next, referring to FIGS. The operation of the abnormality detector 23 will be described.
(1) When the frictional resistance of a movable part such as a brake shoe increases First, the case where the frictional resistance of a movable part such as a brake shoe increases will be described. Even if the frictional resistance of the movable part increases due to some reason such as rusting on the movable part such as the brake shoe 8 and does not become inoperable, the frictional resistance of the movable part instantaneously increases, for example, like a stick-slip phenomenon. When it increases, the jerk j greatly decreases during the suction operation as shown in FIG. Therefore, for example, if the jerk abnormality detection reference value is j _err , a sign of inoperability due to an increase in the frictional resistance of the movable part can be detected by the determination formula shown in formula (3) (STEP 6 in FIG. 3).
j <j _err <0 (3)

In the worst case, when there is no sign that the frictional resistance of the movable part increases momentarily as in the stick-slip phenomenon and the armature 9 becomes inoperable, the armature 9 does not move, so that the contact signal from the brake contact 13 is not output. Therefore, for example, when the abnormality detection reference value of the suction time is T _{pull_err} , the inoperability can be detected by the determination formula shown in the formula (4) (STEP 7 in FIG. 3).
T> T _{pull_err} (4)
Even when the suction force is insufficient due to the short circuit of the brake coil 11 or the resistance is increased, or when the output failure of the brake contact 13 occurs, it can be detected by the equation (4).

When there is no frictional resistance of the movable part and the armature 9 is normally sucked, an ON signal indicating that a certain distance has been sucked from the brake contact 13 is output (STEP 8 in FIG. 3), and the estimated displacement when the ON signal is output _{Xsw_on} = x is temporarily stored in a memory (not shown) inside the brake abnormality detector 23 ( _{STEP 9 in} FIG. 3).

Further, when the armature 9 is attracted and attracted to the electromagnet 12 and the braking torque generated in the brake drum 6 is released, the speed v of the armature 9 becomes zero and the induced electromotive force is not generated, and FIG. As shown after T3, the actual current I of the brake coil 11 again increases until reaching a steady state with a certain time constant. Therefore, for example, when the suction completion reference value considering the calculation error is v _pull , the completion of the suction operation can be detected by the determination formula shown in the formula (5) (STEP 10 in FIG. 3).
| V | <v _pull (5)

The displacement x at the point where the completion of the suction operation is detected is calculated by the equation (5) as the gap x _gap between the armature 9 and the electromagnet 12 by the equation (6) (STEP 11 in FIG. 4).
x _gap = x (6)
Further, the brake contact detection position x _sw is calculated by the equation (7) from the gap x _gap calculated by the equation (6) and the estimated displacement x _{sw_on} when the ON signal is output from the brake contact 13 (STEP 12 in FIG. 4). ).
x _sw = x _gap −x _{sw_on} (7)

(2) Case where foreign matter is mixed between armature and electromagnet and biting occurs Next, a case where foreign matter is mixed between armature 9 and electromagnet 12 and biting occurs will be described. FIG. 7 shows the displacement when foreign matter is mixed between the armature 9 and the electromagnet 12 and biting occurs. If caught by foreign matter occurs, but to a position biting from the suction operation start of changes is not normal, the gap x _gap, and x ₀ brake contact detection position x _sw is a value of _normal, x _se0 And smaller than each. Therefore, for example, assuming that the normal gap is x ₀ , the gap abnormality detection reference value is x _err , the upper limit of the brake contact detection position abnormality detection reference value is x _{sw_max} , and the lower limit is x _{sw_min} , these are the gap x _gap , and From the brake contact detection position _xsw , it is possible to detect biting due to foreign matter contamination by the judgment formulas shown in formulas (9) and (10) (STEP 13 in FIG. 4).
x _err <x ₀ −x _gap (9)
x _sw <x _{sw_min} (10)

(3) When the gap increases Next, a case where the gap of the armature 9 increases due to wear of the brake shoe 8 or the like will be described. FIG. 8 shows the displacement when the gap of the armature 9 increases due to wear of the brake shoe 8 or the like. If the gap of the armature 9 is increased, there is no change in the brake contact detection position x _sw, increases compared with x ₀ is the value of the normal only gap x _gap. Therefore, for example, assuming that the normal gap is x ₀ , the gap abnormality detection reference value is x _err , the upper limit of the brake contact detection position abnormality detection reference value is x _{sw_max} , and the lower limit is x _{sw_min} , these are the gap x _gap , and From the brake contact detection position _xsw , an increase in gap can be detected by the judgment formulas shown in the formulas (11) and (12) (STEP 14 in FIG. 4).
x _err <x _gap −x ₀ (11)
x _{sw_min} <x _sw <x _{sw_max} (12)

When an abnormality is detected in the brake abnormality detector 23, a signal indicating the abnormal state is output to the control panel, and when the abnormality is not detected, a signal indicating completion of the suction operation is output to the control panel. When a signal indicating completion of the suction operation is input to the control panel, the brake command is sent to the voltage command calculator 20 so as to lower the applied voltage to the voltage E _hold necessary for holding the suction at a minimum in order to suppress the heat generation of the brake coil 11. Is output (STEP 15 in FIG. 4).

  The coil resistance calculator 26, which is a coil resistance calculation means, has a differentiator (not shown), and the brake suction command, voltage command value E, and coil current value i are input thereto. When a signal indicating completion of the suction operation is input as the brake suction command, for example, the steady state reference value is set to a, and the reference value is compared with the differential value of the coil current to determine the steady state. When it is determined that the steady state is obtained, the coil resistance R is calculated from the voltage command value E and the coil current value i and is output to the control panel (STEP 16 in FIG. 4).

At this time, if the coil resistance R exceeds the range of the reference value (± R _err ), a coil abnormality is output to the control panel (STEP 17 in FIG. 4). Further, when the coil resistance R is within the reference value range (± R _err ), the calculation error associated with the coil resistance variation is reduced by replacing the coil resistance R with the next initial value (STEP 18 in FIG. 4). When a signal indicating completion of the suction operation is input to the control panel and the coil resistance R is within the reference value range (± R _err ), it is determined that there is no abnormality in the brake device, and the hoisting motor 5 moves the car 1 up and down. Be started.

  As is apparent from the above description, according to the electromagnetic brake failure detection device of the first embodiment, the armature operating speed v is estimated from the voltage command value E and the coil current i, and the brake abnormality is detected based on the result. Therefore, it is possible to distinguish and detect the brake abnormality without depending on the operating speed of the armature and the inductance characteristic of the electromagnetic actuator.

  Further, since the estimated armature operating speed v can be fed back to the brake abnormality detector 23, the present invention can be applied to an electromagnetic brake device that can reduce the operating noise of the brake and require quietness.

Embodiment 2. FIG.
Next, a failure detection apparatus for an electromagnetic brake according to Embodiment 2 of the present invention will be described. FIG. 9 is a block diagram of the control device used in the electromagnetic brake failure detection device according to the second embodiment, and FIGS. 10 and 11 are flowcharts showing the operation of the control device during brake suction.

  In the first embodiment, the estimated armature operating speed v is fed back from the armature speed detector 21 to the voltage command calculator 20, but the armature speed detector 21 of the second embodiment shown in FIGS. Thus, in calculating the voltage command value E, the same effect as in the first embodiment can be obtained without feeding back the estimated armature operating speed v from the armature speed detector 21 to the voltage command calculator 20. be able to. Other configurations and operations are the same as those in the first embodiment.

Embodiment 3 FIG.
Next, a failure detection apparatus for an electromagnetic brake according to Embodiment 3 of the present invention will be described. FIG. 12 is a block configuration diagram of a control device used in the electromagnetic brake failure detection device according to the third embodiment.
In the third embodiment, as shown in FIG. 12, the voltage command value E from the limiter 22 is detected by the voltage detector 27, and the operating speed of the armature is estimated using the coil voltage value u that is the output. In the third embodiment, the same effect as in the first embodiment can be obtained. Other configurations and operations in the third embodiment are the same as those in the first embodiment.

  As described above, according to each of the first to third embodiments, the present invention can be applied to a braking device having an electromagnetic actuator that is required to be downsized and quiet. It is possible to obtain an electromagnetic brake failure detection device that can detect a general failure.

DESCRIPTION OF SYMBOLS 1 Car 2 Counterweight 3 Main rope 4 Sheave 5 Hoisting motor 6 Brake drum 7 Electromagnetic brake device 8 Brake shoe 9 Armature 10 Brake spring 11 Brake coil 12 Electromagnet 13 Brake contact 14 Control device 15 Current detector 20 Voltage command calculator 21 Armature speed calculator 22 Limiter 23 Brake abnormality detector 24 Differentiator 25 Integrator 26 Coil resistance calculator 27 Voltage detector

Claims (5)

In the electromagnetic brake failure detection device comprising a control device that excites the brake coil and causes the brake coil to attract the armature to release the braking force of the brake device.
The controller is
Voltage command calculating means for generating a voltage command for exciting the brake coil;
Current detecting means for detecting an excitation current of the brake coil;
A coil resistance calculation means for estimating a resistance value of the brake coil from a voltage command value output from the voltage command calculation means and a current value of the brake coil detected by the current detection means;
Armature speed calculation for estimating the armature speed from the voltage command value generated by the voltage command calculation means, the resistance value of the brake coil estimated by the coil resistance calculation means, and the current value of the brake coil detected by the current detection means Means,
Integrating means for integrating the estimated speed of the armature estimated by the armature speed calculating means and outputting the result;
Differentiating means for differentiating twice the estimated speed of the armature estimated by the armature speed calculating means and outputting the result;
A brake contact for detecting that the armature is attracted to the brake coil and outputting the result;
The difference between the displacement at the completion of the suction operation in the normal state set in advance and the output result of the integrating means at the completion of the suction operation, the displacement at the output of the brake contact in the normal state set in advance and the brake contact By comparing at least one of the difference between the output result of the integrating means at the time of output of the motor and the difference between the jerk during braking operation in a preset normal state and the output result of the differentiating means, Brake abnormality detecting means for detecting an abnormality of the device;
A failure detection device for an electromagnetic brake, comprising:   The electromagnetic brake failure detection device according to claim 1, wherein the attraction force generated in the brake coil is changed while causing the armature speed to follow a preset target speed.   The output result of the integration means at the time of completion of the suction operation is smaller than the displacement at the time of completion of the suction operation in the normal state set in advance, and the difference is not less than a threshold value for determining abnormality, and is set in the normal state When the difference between the displacement at the time of the output of the brake contact in a state and the output result of the integrating means at the time of the output of the brake contact is equal to or greater than a threshold for determining abnormality, the armature and the brake coil 3. The electromagnetic brake failure detection device according to claim 1, wherein foreign matter is detected as being mixed in between.   The output result of the integration means at the completion of the suction operation is larger than the displacement at the completion of the suction operation in a normal state set in advance, and the difference is equal to or greater than a threshold for determining abnormality, and is set in the normal state When the difference between the displacement at the time of the output of the brake contact in a state and the output result of the integrating means at the time of the output of the brake contact is within a threshold for determining abnormality, the armature and the brake coil The electromagnetic brake failure detection device according to claim 1, wherein the failure detection device detects that the gap between the two has increased.   2. The method according to claim 1, wherein when the output result of the differentiating means during a braking operation is equal to or less than a threshold value for determining abnormality, it is detected that an abnormal frictional force is generated in a mechanism portion of the brake device. Item 3. The failure detection device for an electromagnetic brake according to Item 2.

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